I had the same problem on and off, loading exterior save games gave me IFL (infinite loading screen) and a lot of CTDs, freezes and even BSOD system crashes. Here's the cause and solution.
This memory allocation patch helped my game stability a ton. Hope this helps. EDIT I just realized Korakan posted this fix above. Sorry I neglected to see it at the time :p Well this video explains the details and gives a visual aid to the fix he posted :)